1. Field of the Invention
The present invention relates to a method for collecting a tomato pigment. More particularly, it relates to a method for collecting, at high efficiency and by simple means, a tomato pigment useful as a natural coloring matter for foods or as a natural pigment for cosmetics such as rouge, said pigment having high stability against oxidation, lightening, heating and storage, and containing a lycopene complex or a purified product thereof having an average particle diameter of 0.2-10 .mu.m.
2. Description of the Related Art
There have been known techniques for obtaining a deep red-tinged tomato concentrate by mashing tomato, decomposing it with a plant tissue maceration enzyme, passing the resulting mass through an ultrafiltration membrance having a cut-off molecular weight of 120,000-200,000, and obtaining the tomato concentrate from the membrane-retentate (JP-B 59-35580).
A method is also known in which an alkali is added to mashed tomato to separate a carotenoid complex from the vital tissues, with the unnecessary matters such as skins, seeds, fibers, etc., being removed from the separated solution, then an acid is added thereto to have the carotenoid pigment fractionally precipitated, the precipitate being then collected with its pH adjusted close to neutrality or slightly alkalinity and concentrated, followed by addition of an acid to make the product acidic, and then common salt is further added to thereby obtain carotenoid to be used for red coloring of foods (JP-B 55-1311). There is further known a technique for separating lycopene from a pulp fraction as a tomato oleoresin (WO 95/16363). However, since lycopene in the form of oleoresin is an oil, it is required, in use thereof, to make a choice over whether it is left as an oil or mixed with an emulsifier, so that the scope of its use, especially in aqueous foods, is limited.
The tomato concentrates contain richly such insoluble solid matters as pulp, polysaccharides and proteins and such soluble matters as sugars, acids and aromatic substances, and carry heavily a flavor peculiar to tomato, so that they have a disadvantage in that the scope of its use as a pigment is limited, and also the lycopene content is low.
Said carotenoid for food coloration, although characteristically high in lycopene content, requires use of an alkali and an acid in preparation thereof and necessitates a very complicated production process, and further, since the products containing carotenoid have a salty taste, its use in foods and cosmetics as a pigment is necessarily restricted.